Question

1. in a paper - mill, which material is the feedstock?

a) pulp
b) wood chips
c) drying machines
d) ink

1. throughput refers to:

a) the percentage of feedstock turned into product
b) the movement of materials on a diagram
c) how much material is processed in each time
d) the final products quality

1. a refinery producing 10,000 barrels per day is describing its:

a) refinery
b) throughput
c) off - spec production
d) mass balance

1. if 200 lbs of feedstock produces 160 lbs of product, the yield is:

a) 80%
b) 20%
c) 100%
d) 50%

1. high yield usually means:

a) more waste and lower profit
b) less waste and higher profit
c) products are off - spec
d) lower throughput

1. an off - spec product is one that:

a) meets safety standards
b) is produced at high yield
c) fails to meet quality standards
d) increases throughput

1. off - spec products are dangerous because they:

a) waste money and harm reputation
b) improve yield and safety
c) increase throughput
d) always make higher profits

Explanation:

Step1: Define yield formula

Yield = $\frac{\text{Mass of product}}{\text{Mass of feed - stock}}\times100\%$

Step2: Calculate yield for question 5

Given mass of feed - stock = 200 lbs and mass of product = 160 lbs. Yield = $\frac{160}{200}\times100\% = 80\%$

Step3: Understand high - yield concept for question 6

High yield means more of the feed - stock is converted into product, so less waste and higher profit.

Step4: Define off - spec product for question 7

An off - spec product fails to meet quality standards.

Step5: Understand danger of off - spec products for question 8

Off - spec products waste money (due to re - work or disposal) and harm reputation.

Answer:

1. a) Wood chips
2. a) The percentage of feedstock turned into product
3. b) Throughput
4. a) 80%
5. b) Less waste and higher profit
6. c) Fails to meet quality standards
7. a) Waste money and harm reputation