3520 Chapter 28 



The unit evaluated is designed for a flow-through rate of 3 tons of wood per 

 hour (ovendry basis). This 3 tons of wood contains about 51 million Btu; output 

 is about 43.3 million Btu/hour for an efficiency of about 85 percent, with 

 products as follows: 



Pyrolysis product and Weight Energy 



energy content (Btu/pound) output output 



Pounds/hour million Btu/hour 



Charcoal (12,834) 2,000 25.7 



Oil (9,573) 1 ,000 9.6 



Gas (4,000) 2,000 8.0 



Total 5,000 43.3 



In analyzing economic feasibility of the operation, cost of delivered hardwood 

 chips was estimated at $12/green ton for wood averaging 40 percent moisture 

 content (wet- weight basis). Annual wood consumption was projected to be 

 21,000 tons (ovendry basis) or 35,000 tons on a green- weight basis. Charcoal 

 production was estimated at 7,000 tons/year with sales price of $80/ton less $5/ 

 ton transport cost for delivery to the user. Annual production of pyrolysis oil and 

 gas was estimated at 100 billion Btu, with sales price of $3.50/million Btu. 



Key statistics projected for the enterprise are as follows: 



Capital investment $700,000 



Operating cost, annual $680,000 



Sales, annual $910,000 



Net profit, annual (before income tax) $230,000 



Return on sales 25 percent 



Return on investment 33 percent 



Employees 7 



Energy requirement, annual 



Electrical 150,000 kWh 



Oil (for system start-up) 3,500 gal 



Wood 357 X 10^ Btu 



Klein (1981) points to potentially great expansion of demand for charcoal and 

 pyrolytic oil as non-polluting extenders for blending with high-nitrogen and 

 high-sulfur coals to reduce their stack pollutant concentration. Best prospects for 

 use of the low-Btu gas from the process are at heating or energy installations 

 where it can be burned efficiently while still hot from the pyrolyzer. 



28-11 $718,038— SHORT-LOG PROCESS FOR 

 PRODUCING PALLET PARTS AND PULP CHIPS ' 



The projected single-shift, 240-day/year operation requires a daily input of 38 

 cords of hardwood bolts 52 inches long and 5.5 to 1 1 .5 inches in diameter. From 

 each cord, about 525 board feet of pallet parts are produced in a mill equipped 

 with a two-saw skrag mill (figs. 18-119 and 28-13 top) and resaws. The oper- 

 ation, producing 20 Mbf daily of 40-inch-long deckboards cut 3y4 or 5y4 inches 



'■'Abstracted from Hansen and Reynolds (1981). 



