Paper 2 Flashcards
Things that can go wrong with a catalyst
degradation e.g. sintering which reduces surface area, sulfur poisoning Pd by attaching to active sites, coking blocking access to surface of catalyst, thermal degradation, lifetime too short, someone else has the IP, may need high pressure leading to reactor failure
WFLITTENC
Waste, Financials, Location, Ingredients, Timescale, Toxics, Employment, Novelty, Catalyst
cash flow
net amount coming into a company in a set period of time. =income-expenditure
profit
sales revenue - total costs
gross profit is income minus expenditure, i.e. cash flow
taxable profit is profit minus allowance
net profit is gross profit minus tax
working capital
money needed to start up and run the plant before any sales generated. some recovered at end of project
can land be written off against tax?
no
book value of an asset
the depreciated value of the asset = historic cost minus accumulated depreciation
straight line depreciation
spreads the cost of the asset evenly through its useful life
declining balance or fixed annual percentage
e.g. annual depreciation charge=0.25*book value for each year.
which depreciation method should you use?
straight line for IP and buildings
UK prefers declining balance methods
are taxes rounded up or down?
down
“scrap value at the end of 6 years”
put the scrap in the year 5 row
limitations of RORI
only valid for an average year so doesn’t allow for changes in profits
does not consider time value of money
incremental RORI
further benefit over further cost
i.e. extra saving generated by the extra investment
interest
benefit gained without taking any risk
npv index
npv over capital required
for a project to be viable, want high NPV (>0) and high i* st the discount rate i is less than i* for the project
FAR
Number of deaths per 10^8 exposed hours (corresponding to a workforce of 1000 working for 50 years at 50 weeks per year and 40 hours per week)
how do chem eng’s write the second law of thermodynamics
dS=dq/T + dSgen where the dq is the same as dq appearing in the first law
dU=dq+dws-pdV
COP refrigeration cycle
do you want big or small COP?
COP refrig = heat in/net work in = ‘HINWI’
want small COP
what does presence of Re suggest
fluid flow, inertial and viscous forces present
what does Fr suggest
ratio of KE/PE where energy interchange btw these two forms is involved. suggests fluid flow subject to gravity/buoyancy
does temp change when you pass through a valve?
if ideal gas then no because isenthalpic, if real gas then temp changes even if isenthalpic
When was the Health and Safety at Work Act passed?
1974
concept of reasonably practicable
weighing a risk against the trouble, time and money needed to control it
decision weighted in favour of h & s
to avoid making sacrifice, duty-holder must demonstrate that the sacrifice is grossly disproportionate to the benefits of risk reduction that would be achieved
