Process Yield and Capacity

Yield and throughput

Process mass yield is accepted product divided by total feed. Producing 800 kg from 1000 kg of feed gives an 80 percent yield. Over an eight hour period including downtime, average feed is 125 kg/h and product throughput is 100 kg/h. With a rated feed capacity of 200 kg/h, period utilization is 62.5 percent.

Estimating production

The planning mode multiplies rated feed capacity by period duration and operating fraction, then applies mass yield. A 200 kg/h feed capacity over eight hours at 75 percent operating time and 80 percent yield gives 960 kg of product. Include all added streams in feed. Do not compare dry feed with wet product. Inventory accumulation and different product grades require separate assessment.

Separate downtime from material loss

For a planning example, choose rated feed capacity of 150 kg/h, a period of 10 h, an operating fraction of 80 % and a mass yield of 90 %. Operating time is 10 × 0.80 = 8 h. The feed processed is 150 × 8 = 1200 kg. Accepted product is 1200 × 0.90 = 1080 kg. Spread over the full period, product output is 1080 / 10 = 108 kg/h. These inputs illustrate the calculation and do not describe the capacity of a particular plant.

Operating fraction and product yield answer different questions. Raising operating fraction increases the time available for production. Raising yield increases the accepted product mass obtained from the same feed. Treating them as the same loss factor can count downtime twice. Track work in progress at the beginning and end of the measurement period separately. Mass missing from accepted product is not automatically waste. It may include byproducts, recycled streams or an inventory change. Compare periods using the same product acceptance criteria, moisture basis and feed boundary. Keep rated feed capacity separate from average product output over the whole period.

Frequently asked questions

How do you calculate process yield?

For an example feed mass of 1000 kg producing 800 kg of accepted product, dividing output mass by input mass gives a process yield of 80 percent. All added materials must be included in feed, dry and wet masses must not be mixed, and stock accumulation or different product types need separate assessment.

Calculate with these values