If you could download the ISO standard ( BS EN ISO 18125 ) for determining the heating value of pellets and briquettes may be you can find another procedure that you can follow easily to determine the HHV rather than using the bomb calorimeter.

https://www.techstreet.com/standards/bs-en-iso-18125-2017?product_id=1989566

Dear Dr M. Okwu,

There are simple alternative routes that can be used to determine the HHV of briquettes or any other biomass material.

One of such ways to carryout the proximate analysis of the sample and subsequently calculate the HHV using one of many relations available in literature (see attachments).

Alternatively, the elemental composition can be determined by ultimate analysis and the HHV also calculated using any one of the relations. Hope this helps.

Best regards,

BBN

Please look for the works of Sotande A Olufemi who has worked extensively on briquette

https://www.researchgate.net/profile/Olufemi_Sotannde?_iepl%5BgeneralViewId%5D=izckipW1a91VXnkg1QdeTf8mchj0RpXnLdvL&_iepl%5Bcontexts%5D%5B0%5D=searchReact&_iepl%5BviewId%5D=sfxgqmnE5JNrXHsbcOH6TlLCtvcsp3VOYWEf&_iepl%5BsearchType%5D=researcher&_iepl%5Bdata%5D%5BcountMoreThan20%5D=1&_iepl%5Bdata%5D%5BinteractedWithPosition1%5D=1&_iepl%5Bdata%5D%5BwithEnrichment%5D=1&_iepl%5Bposition%5D=1&_iepl%5BrgKey%5D=AC%3A8841425&_iepl%5BinteractionType%5D=profileView

Following....Thank you all for the information

Thank you so much for the useful information - Mohammed, Elsaid, Bemgba, Chukwu and Adedoyin.

Interesting feedback...

Calorific value of solid briquette fuel can be determined by employing the Dulong formula as indicated in Eq. (1)

QHHV (Mj/kg) = 33.83C + 144.3(H- O/8) (1)

where C, H, O represents the mass fractions of carbon, hydrogen, and oxygen respectively (Probstein and Hicks, 1982).

Thank you prof. O.D.Samuel.

Useful information from Bemgba B. Nyakuma