Bomb Calorimetry.docx

Bomb Calorimetry A bomb calorimeter is a constant volume calorimeter (constant volume is isochoric). So the heat measured by such an instrument is equivalent to the change in internal energy or ΔUΔU. The heat can be determined from the temperature change, ΔTΔT, and the heat capacity of the calorimeter, CcalCcal. For a bomb calorimeter, the heat capacity is usually quite large due to all the water and the hardware (stirring paddles, blades, the stainless steel "bomb" holding the reactants, the wiring, the walls of the calorimeter, etc...). This value is CcalCcal. It is used to find qvqv of the system:

qcal=CcalΔT=−qv,systemqcal=CcalΔT=−qv,system Sometimes, it is more convenient to split the overall heat capacity of the calorimeter into its component parts: (1) the water, and (2) the hardware.

Ccal=Chardware+mwaterCs,waterCcal=Chardware+mwaterCs,water The hardware heat capacity will be in units of J/K or kJ/K while the water heat capacity has to be calculated from the mass of the water and the specific heat of water (4.184 J g-1 K-1). So the water part is slightly variable due to the fact that you can fill the calorimeter up with slightly different masses of water each time you use it. If you put all that into one formula for a bomb calorimeter, you get:

qcal=ChardwareΔT+mwaterCs,waterΔTqcal=ChardwareΔT+mwaterCs,waterΔT One last thing to note. Many tables will list heat capacities using °C instead of K. Realize that these two units are equivalent in this context because we are using ΔTΔT and not plain TT. A change in Kelvin of 10 is exactly a change of 10 in °C as well. So don't try to change Celsius to Kelvin and vice versa here. This will be true throughout all your science courses.

Converting ΔUΔU to ΔHΔH Chemists are almost always interested in the enthalpy change to know what would have happened at constant pressure. It is possible to get ΔHΔH from a bomb calorimeter experiment. It just takes an additional step to do a conversion from ΔUΔU to ΔHΔH. To convert from ΔUΔU to ΔHΔH requires knowing the amount of work done (ww) during the reaction. In the case of a chemical reaction, work can be easily calculated by simply counting the number of moles of gas products and gas reactants.

Δngases=Σngasproducts−ΣngasreactantsΔngases=Σngasproducts−Σngasreactants Now the work can be calculated with the formula:

work:w=−ΔngasesRTwork:w=−ΔngasesRT So this leads to the final formula for the conversion:

ΔU=ΔH−ΔngasesRTΔU=ΔH−ΔngasesRT or with a little algebraic rearranging...

ΔH=ΔU+ΔngasesRT

https://ch301.cm.utexas.edu/section2.php?target=thermo/thermochemistry/bomb-calorim.html

Introduction The Boys gas calorimeter is a simple and effective means of measuring gases calorificvalues. The Boys gas Calorimeter is named after an English physicist called Sir Charles Boys (1855-1944). It is the standard piece of equipment used to calculate theHigher Calorific (HCV) and the Lower Calorific (LCV) of gases.Calorimetry is the name given to the measurement of heat. When a fuel is burnt atconstant pressure the energy transferred as heat to the surroundings per unit quantityof fuel is called the calorific value. The products of combustion will be at the sametemperature as the fuel and air (reactants). If condensation occurs in the water on the products side then the Higher Calorific value is determined, However if the water remains in the vapour phase then the Lower Calorific value is sought. Objective To determine the higher and lower calorific values of natural gas. (HCV and LCV).Sometimes referred to as the gross calorific value and the net calorific value. Method The most important part of this experiment was to measure all constant values beforewe started. This involved recording the gauge pressure, volume of gas, inlet temperature, exhaust temperature, the temperature in and out of the cooling water andthe time which in the case of this experiment would be 60 seconds.The experiment was repeated four times, the first two times the experiment was set upso that the higher calorific value of the natural gas could be determined. The reason itwas done twice was to try to ensure accuracy of results. For the second part of theexperiment we set the apparatus up so that the lower calorific value could bedetermined. The way this was done was to reduce the volume of gas in the cylinder. Figure 1a: The Boys’ Gas Calorimeter When the experiment is ready to start a beaker is placed under the tap that allows thecooling water out and the pipe that that carries the condensate is moved from a position of waste to that of being collected into a separate beaker. The time for theexperiment was recorded using a normal stopwatch; in this case we decided to do theexperiment for 60 seconds. Theory PressureicAtmospherPressureGaugePressureAbsoluteghpressue Gauge1002gasof Volumelitretodmfromgasof VolumeChanging 3 +=×⇒ ρ

(l)heatlatentspecificm(mass)(Q)heatLatentVWaterOf Mass60Vol umeCorrectedRateFlowVolumeVV VolumeCorrected273.15C)(Te mpKelvintoCConvert 21212121 ×=⇒==+ ρ TTVTTV OHof heatlatentspecificcollectedcondensateof mass)(C))151barus ed(atfuelof (volumewater)of risere(Temperatucapacity)heat(spe cificwater)coolingof (mass 2 °×= Fuel of Volume LCV HCV HCV Results Discussion It appears from published values of natural gas’ higher calorific values and lower calorific that we were not to far away with our values. Having said that there doesappear to quite a large error margin for our last attempt with a value of 103050 for theHCV appearing to be extremely high. The most apparent error here seems to be therise in temperature of the water. The rise in temperature was concurrent with the firsttwo parts of the experiment i.e. 35K however in my opinion the rise in temperature of the water should have been considerably less. The reason for this error could beexplained away by human error, not reading the thermometer correctly or there couldhave been a more serious flaw in that there may have been an equipment malfunction.Another possible source of error may have been to do with a rise in the ambienttemperature.It does appear that for the main our values were quite accurate and consistent withknow data for HCV and LCV of natural gas Conclusion

The Boys Gas Calorimeter is a very useful way of measuring out experimentally theHCV and LCV of different gases. American power plants prefer to use the higher calorific values (gross calorific value) to measure the thermal efficiency of their power plants, whereas the Europeans prefer to us the lower calorific value (netcalorific value)

https://www.pdfcoke.com/doc/154609859/The-Boys-Gas-Calorimeter This Gas Calorimeter works on the Junker's principle of burning of a known volume of gas and imparting the heat with maximum efficiency to steadily flowing water and finding out of the rise in temperature of a measured volume of water. The formula, Calorific Value of Gas X Volume of Gas = Volume of water X Rise in Temperature, is then used to determine the Calorific Value of the Gas (assuming that heat capacity of water is unity). EQUIPMENT This equipment consists of the Calorimeter with Powder Coated Stainless Steel exterior with burner (with choice of two nozzles) on a tripod stand, a Gas Flow Meter (Cat. No. IRI 08) and a pressure governor. Requisite tubing & measuring jars as well as thermometers (0.1oC graduation) for reading inlet & outlet water temperatures are also provided along with a detailed instruction manual. Calorimeter This Calorimeter covers a wide range between 120 BTU (1000 to 26000 K Cal/m 3). The Calorimeter is fixed on a tripod stand having leveling screws to keep the Calorimeter in perfectly vertical position. The Calorimeter mainly consists of a gas combustion chamber, heat exchanger and water flow system. Heat exchanger is designed for maximum efficiency of heat transfer and is fabricated out of heavily tinned copper sheet. A constant water head maintenance device provided in the feed water pipe along with the inlet water flow regulator is fixed to the outer housing of teh Calorimeter. The outer housing is of powder coated stainless steel. This constant water level attachment has an over flow device through which excess water drains out. Water from this constant head device enters the bottom of the heat exchanger through inlet water flow regulator and raised along the annular space, comes up to the filtering position at

the top and gets collected at the swinging funnel attachment. While going up it absorbs the heat generated by burning the gas in the burner located at the bottom of the central chamber of the Calorimeter. Two thermometers are provided in the water inlet and outlets ports. Temperature of the effluent gas can be measured from the thermometer fixed at the exhaust gas outlet. Provision for fixing the burner is provided at the Calorimeter base. An outlet for collection of condensate is provided at the bottom. Gas Flow Meter The Gas Flow Meter Provided is Cat. No. IRI 08. It is a wet type Gas Flow Meter, with recording facility on a mechanical counter of the number of revolutions made, which gives total volume of gas burnt, For more details of the Flow Meter, please refer to its individual leaflet. Pressure Governor This is to regulate the pressure of gas before it enters the flowmeter. These governors are factory adjusted for a required pressure. Specifications are subject to change without notice

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Definition of Orsat Apparatus : an apparatus for gas analysis that consists essentially of a measuring burette, a connected series of pipettes containing selective absorbents, and usually a combustion pipette https://www.merriam-webster.com/dictionary/Orsat%20apparatus https://www.slideshare.net/dhruvupadhaya/orsat-apparatus

ASTM E1755 - 01(2007)

Standard Test Method for Ash in Biomass SUPERSEDED (click for Active standard) Format

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Reprints and Permissions Permissions to reprint documents can be acquired through Copyright Clearance Center VISIT COPYRIGHT CLEARANCE CENTER Active (view current version of standard) Other Historical Standards ASTM License Agreement MORE E48.05 STANDARDSRELATED PRODUCTS 1. Scope 1.1 This test method covers the determination of ash, expressed as the mass percent of residue remaining after dry oxidation (oxidation at 575 ± 25°C), of hard and soft woods, herbaceous

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materials (such as switchgrass and sericea), agricultural residues (such as corn stover, wheat straw, and bagasse), wastepaper (such as office waste, boxboard, and newsprint), acid and alkaline pretreated biomass, and the solid fraction of fermentation residues. All results are reported relative to the 105°C oven-dried mass of the sample. For particulate wood fuels, Test Method E 1534 should be used. 1.2 The values stated in SI units are to be regarded as the standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. https://www.astm.org/DATABASE.CART/HISTORICAL/E1755-01R07.htm

ASTM E870 - 82(2013)

Standard Test Methods for Analysis of Wood Fuels Active Standard ASTM E870 | Developed by Subcommittee: E48.05 Book of Standards Volume: 05.06 Format

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Reprints and Permissions Permissions to reprint documents can be acquired through Copyright Clearance Center VISIT COPYRIGHT CLEARANCE CENTER Historical Version(s) - view previous versions of standard ASTM License Agreement Shipping & Handling MORE E48.05 STANDARDSRELATED PRODUCTSSTANDARD REFERENCES Significance and Use

4.1 These test methods of analysis described herein can be used for the proximate analysis, ultimate analysis, and the determination of the gross caloric value of wood fuels. 1. Scope 1.1 These test methods cover the proximate and ultimate analysis of wood fuels and the determination of the gross caloric value of wood fuels sampled and prepared by prescribed test methods and analyzed according to ASTM established procedures. Test methods as herein described may be used to establish the rank of fuels, to show the ratio of combustible to incombustible constituents, to provide the basis for buying and selling, and to evaluate for beneficiation or for other purposes. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. https://www.astm.org/Standards/E870.htm

ASTM E1358 - 97(2013)

Standard Test Method for Determination of Moisture Content of Particulate Wood Fuels Using a Microwave Oven Active Standard ASTM E1358 | Developed by Subcommittee: E48.05 Book of Standards Volume: 05.06 Format

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Shipping & Handling MORE E48.05 STANDARDSRELATED PRODUCTSSTANDARD REFERENCES Significance and Use 4.1 This test method provides a rapid determination for moisture in particulate wood fuels in several minutes. The standard method, E871, requires a minimum of 18 h. This method is applicable to situations such as the spot-check of the moisture delivered by truck where a quick indication of the moisture of wood delivered is desirable. 1. Scope 1.1 This test method provides an alternative method to Method E871, for the determination of the moisture of particulate wood fuels. Particulate wood fuels are defined in E1126. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. https://www.astm.org/Standards/E1358.htm

ASTM E871 - 82(2013)

Standard Test Method for Moisture Analysis of Particulate Wood Fuels Active Standard ASTM E871 | Developed by Subcommittee: E48.05 Book of Standards Volume: 05.06 Format

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Historical Version(s) - view previous versions of standard ASTM License Agreement Shipping & Handling MORE E48.05 STANDARDSRELATED PRODUCTSSTANDARD REFERENCES Significance and Use 4.1 The test procedures described in this test method can be used to determine the total weight basis moisture of any particulate wood fuel meeting the requirements specified in this test method. 1. Scope 1.1 This test method covers the determination of total weight basis moisture in the analysis sample of particulate wood fuel. The particulate wood fuel may be sanderdust, sawdust, pellets, green tree chips, hogged fuel, or other type particulate wood fuel having a maximum particle volume of 16.39 cm3 (1 in.3). It is used for calculating other analytical results to a dry basis. Moisture, when determined as herein described, may be used to indicate yields on processes, to provide the basis for purchasing and selling, or to establish burning characteristics. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. https://www.astm.org/Standards/E871.htm

ASTM D1102 - 84(2013)

Standard Test Method for Ash in Wood Active Standard ASTM D1102 | Developed by Subcommittee: D07.01 Book of Standards Volume: 04.10

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Reprints and Permissions Permissions to reprint documents can be acquired through Copyright Clearance Center VISIT COPYRIGHT CLEARANCE CENTER Historical Version(s) - view previous versions of standard ASTM License Agreement Shipping & Handling MORE D07.01 STANDARDSRELATED PRODUCTSSTANDARD REFERENCES Significance and Use 2.1 The ash content is an approximate measure of the mineral content and other inorganic matter in wood. 1. Scope 1.1 This test method covers the determination of ash, expressed as the percentage of residue remaining after dry oxidation (oxidation at 580 to 600°C), of wood or wood products. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. https://www.astm.org/Standards/D1102.htm

Designation: E 872 – 82 (Reapproved 1998) standard Test Method for Volatile Matter in the Analysis of Particulate Wood Fuels 1 This standard is issued under the fixed designation E 872; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (

e ) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This test method determines the percentage of gaseousproducts, exclusive of moisture vapor, in the analysis sample of p a r t i c u l a t e w o o d f u e l t h a t i s r e l e a s e d u n d e r t h e s p e c i fi c c o n d i t i o n s o f t h e t e s t . Th e p a r t i c u l a t e wo o d f u e l ma y b e sanderdust, sawdust, pellets, green tree chips, hogged fuel, orother type particulate wood fuel having a maximum particlevolume of 16.39 cm 3 (1 in. 3 ). Volatile matter, when determineda s h e r e i n d e s c r i b e d , m a y b e u s e d t o i n d i c a t e y i e l d s o n processes to provide the basis for purchasing and selling or toestablish burning characteristics.1 .2 Th e v a l u e s s t a t e d i n S I u n i t s a r e t o b e r e g a r d e d a s t h e standard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thes a f e t y c o n c e r n s , i f a n y , a s s o c i a t e d w i t h i t s u s e . I t i s t h e responsibility of the user of this standard to establish appro priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D 346 P r a c t i c e f o r C o l l e c t i o n a n d P r e p a r a t i o n o f C o k e Samples for Laboratory AnalysisD 2013 Method of Preparing Coal Samples for AnalysisE 871 Method for Moisture Analysis of Particulate WoodFuels 3. Summary of Test Method 3.1 Volatile matter is determined by establishing the loss inweight resulting from heating wood under rigidly controlledconditions. The measured weight loss, corrected for moistureas determined in Method E 871, establishes the volatile mattercontent. 4. Significance and Use 4.1 The test procedures described in this test method can beused to determine the percentage of gaseous products, exclu-sive of moisture vapor, of any particulate wood fuel meetingthe requirements specified in this test method. 5. Apparatus

5.1 Platinum Crucible , w i t h c l o s e l y fi t t i n g c o v e r , o r a nickel-chromium crucible, with closely fitting cover, pre-firedto oxidize and stabilize the weight. The crucible shall be of notless than 10 or more than 20-mL capacity, not less than 25 ormore than 35 mm in diameter, and not less than 30 or morethan 35 mm in height.5.2 Vertical Electric Tube Furnace —The furnace may be of the form shown in F i g . 1 . It shall be regulated to maintain atemperature of 950 6 20°C in the crucible, as measured by athermocouple positioned in the furnace. 6. Procedure 6.1 Sampling :6.1.1 Place of Sampling —Take sample where wood is beingloaded into or unloaded from means of transportation or whendischarged from storage bins or conveyors. N OTE 1—Samples collected from the surface of piles are, in general,u n r e l i a b l e b e c a u s e o f t h e e x p o s u r e t o t h e e n v i r o n me n t . I f n e c e s s a r y, c o l l e c t n i n e i n c r e me n t s f r o m a f o o t o r mo r e b e l o w t h e s u r f a c e a t n i n e points covering the pile. 6.1.2 Collection of Gross Sample :6.1.2.1 Collect increments regularly, systematically, andwith such frequency that the entire quantity of wood sampled will be represented proportionally in the gross sample.6.1.2.2 The quantity of the sample shall be large enough tobe representative but not less than 10 kg (22 lb).6.1.2.3 Place samples in an airtight container immediatelyafter collection. Maintain samples in the airtight containerwhenever possible to prevent gains or losses in moisture fromthe atmosphere.6 .1 .3 S a mp l e r e d u c t i o n ma y b e d o n e b y t w o me t h o d s , a c o n i n g a n d d i v i d i n g p r o c e s s , o r b y u s i n g a r i f f l e . M i x i n g , coning, and quartering are described and illustrated in PracticeD 346. 1 T h i s t e s t me t h o d i s u n d e r t h e ju r i s d i c t i o n o f AS TM C o mmi t t e e E 4 8 o n Biotechnology and is the direct responsibility of Subcommittee E48.05 on

BiomassConversion Systems.Current edition approved May 28, 1982. Published December 1982. 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at [email protected]. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page onthe ASTM website https://www.pdfcoke.com/document/362201015/Astm-e872-82

Thermogravimetry Analysis (TGA)

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Hyphenated techniques couple TGA and other instruments to gain insights previously unseen by either technique on its own. Systems for TG-FT-IR, TG-MS, and TG-GC/MS help you gain better insight and advance your research. http://www.perkinelmer.com/category/thermogravimetry-analysis-tga